JP2547321Y2 - Switching valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a switching valve, and is particularly effective when applied to an elastic seal type and a two-position or three-position switching valve having a spool-shaped main shaft. Technology.

[Conventional technology]

In this type of switching valve, a shaft hole is formed in the valve body along the axial direction, an input port, an output port, and a discharge port communicate with the shaft hole, and a main shaft is movably provided in the shaft hole. An annular elastic seal is fitted to one of the main shafts,
The passage between the ports can be switched by moving the main shaft between two positions, and the shaft hole or the seal sliding portion of the main shaft has the same diameter over the entire length in the axial direction. .

[Problems to be solved by the invention]

However, in the configuration of the switching valve, since the seal hole of the shaft hole or the main shaft has the same diameter over the entire length in the axial direction, the sliding distance and the frictional resistance of the elastic seal are large. As a result, the elastic seal wears out, deteriorating the sealing performance, and has a problem that the life is short.

In addition, the seal sliding portion must be uniformly processed with a high surface roughness over the entire length in the axial direction, and there is a problem that the processing cost is high. Furthermore, since the elastic seal is a squeeze-type elastic seal that seals with a restoring force due to tightening, that is, a squeeze packing or a squeeze seal, there has been a problem that the sticking phenomenon causes poor operability at the start of work.

The present invention has been made in view of the above problems, and its object is to reduce the sliding distance and frictional resistance of the elastic seal, reduce the wear of the elastic seal, extend the service life, and reduce the processing cost. It is an object of the present invention to provide a switching valve that can reduce the cost of the device, prevent the stick phenomenon from occurring, improve the operability at the start of work, and improve the durability.

[Means for solving the problem]

In the present application, the outline of a representative invention among the disclosed inventions is briefly described as follows.

The switching valve of the present invention has a valve body having an input port, an output port, and a discharge port formed with an axial hole formed in the axial direction and communicating with the axial hole, and movably in the axial hole. A switching valve for switching a flow path between the ports, wherein a squeeze-type elastic seal that elastically expands and contracts in a radial direction is attached to one of the valve body and the main shaft. The other of the valve body and the main shaft has a diameter substantially corresponding to the diameter of the seal surface of the elastic seal, and the tightening margin of the elastic seal during movement of the main shaft is small or substantially the same. A sliding portion that does not occur, and a seal portion that is connected to the sliding portion in the axial direction and contracts and deforms the elastic seal with a large interference in the radial direction by the subsequent movement of the main shaft are formed. Wherein the diameter to each other and the seal sliding portion of the stepped structure differs by a Lumpur portion.

[Action]

According to the switching valve of the present invention, the seal sliding portion of the shaft hole or the main shaft is formed of the sliding portion and the seal portion connected to the sliding portion, and the diameter changes between the seal portion and the sliding portion. Due to the stepped structure, the interference of the elastic seal is reduced in the sliding portion, and the elastic seal slides a short distance and stops at the switching position in the seal having a large interference. As a result, the sliding distance and frictional resistance of the elastic seal are reduced, the wear of the elastic seal is reduced, and the life is extended,
The processing cost can be reduced, the stick phenomenon can be prevented, the operability at the start of work can be improved, and the durability of the switching valve can be improved.

Since the sliding portion has a diameter of a size in which the interference of the elastic seal is substantially reduced or substantially does not occur, the interference of the elastic seal is significantly reduced in the sliding portion. As a result, the sliding distance and the frictional resistance of the elastic seal can be further reduced, and the wear of the elastic seal can be further reduced to extend the life. Therefore, an increase in sliding resistance due to wear of the squeeze-type elastic seal is prevented, and the operating resistance at the start of starting the spindle is reduced, so that the spindle can be driven smoothly.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

Embodiment 1 FIG. 1 is a cross-sectional view showing a switching valve according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view showing details of a main part of the switching valve.

In the first embodiment, the switching valve is of an elastic seal type and a two-position type, and includes a main valve 1 and a pilot valve 2.
And the solenoid unit 3 are coaxially connected.

The main valve 1 has a shaft hole 5 at the center of the main valve body 4, an input port 6 communicating with the shaft hole 5, first and second discharge ports 7, 8, and first and second output ports 9. , 10 are formed. A spool-shaped main shaft 11 is movably provided in the shaft hole 5. The main shaft 11 has small-diameter portions 12, 12a, 12b and large-diameter portions 13, 13a formed alternately, and the large-diameter portions 13, 13a have elasticity. A squeeze packing 15 as a body seal is fitted.

The main pilot passage 16 opening at the position of the shaft hole 5 facing the input port 6 includes first and second sub pilot passages 16.
Branched to a and 16b.

The first sub-pilot passage 16a extends leftward and is connected to a first fluid chamber 18 in the end cover 17. Spindle
A first piston 19 that urges the rightward moving force to 11 is slidably provided in the first fluid chamber 18.

The second auxiliary pilot passage 16b extends rightward and is connected to the pilot valve 2. The pilot valve 2 has second and third fluid chambers 21 and 24 on the left and right sides of the pilot valve body 20. doing. A second piston having a larger pressure receiving area than the first piston 19 is provided in the second fluid chamber 21.
22 is provided slidably, a second fluid chamber 21 is partitioned to the left fluid chamber 21 _L and a right fluid chamber 21 _R by the second piston 22.

The left fluid chamber 21 _{L communicates} with the pilot discharge port 23,
Right fluid chamber 21 _R communicates with the pilot discharge port 23 through the first valve seat 14, the second auxiliary pilot passage 16b to the third fluid chamber 24 is communicated through the second valve seat 25 I have.

A communication passage 26 is formed between the right fluid chamber _21R and the third fluid chamber 24, and a plunger pin 27 is provided in the communication passage 26. By moving the plunger pin 27 to the left, the flapper 28 can be separated from the first valve seat 14 against the urging force of the flapper spring 29.

The solenoid unit 3 includes a fixed core 31 in the bobbin 30 and a plunger 32 magnetically attracted to the fixed core 31. The plunger 32 protrudes into the third fluid chamber 24, and a poppet 33 is provided at the tip. Fitted, plunger spring 34
Urges the second valve seat 25 and the plunger pin 27 with the tip surfaces of the poppet 33 and the plunger 32.

A solenoid coil 35 for generating a magnetic force on the fixed core 31 by energization is wound around the outer periphery of the bobbin 30, and the solenoid coil 35 is covered with a solenoid cover 36.

The main point of the first embodiment is that the main valve 1 has an annular valve seat 37 formed on the inner peripheral surface of the shaft hole 5.
The difference lies in that a seal sliding portion 45 having a stepped structure is formed.

That is, the seal sliding portion 45 formed on the valve seat 37 is formed of a seal portion 38 and a sliding portion 39 connected to the seal portion 38 with a smooth curved surface, and the sliding portion 39 and the seal portion 38 are formed. The seal part 38 is formed with a small diameter.
The squeeze packing 15 is formed so as to have such a large diameter as to be in contact with the inner peripheral surface thereof or not, so that the interference of the squeeze packing 15 is reduced or the interference is not substantially generated.

 Next, the operation of the first embodiment will be described.

FIG. 1 shows a normal state in which the main shaft is in the right switching position by the biasing force of the first piston by air pressure. In this normal state, the input port 6 and the first output port 9 communicate with each other by the space between the small diameter portion 12a of the main shaft 11 and the shaft hole 5,
The space between the small diameter portion 12b of the main shaft 11 and the shaft hole 5 allows the second output port 10 and the second discharge port 8 to communicate with each other.

When the path is switched by moving the main shaft 11 in the normal state to the left, when a current is applied to the solenoid coil 35 of the solenoid unit 3, a magnetic force is generated in the fixed core 31, and the plunger 32 is moved to the fixed core 31 by the magnetic force. Accordingly, in the third fluid chamber 24, the second valve seat 25 is opened by the separation of the poppet 33, and the application of the pressing force to the plunger pin 27 is released.

Therefore, the flapper 28 closes the first valve seat 14 by the urging force of the flapper spring 29, and the right fluid chamber 21 _R airtight, supplying auxiliary air to the right fluid chamber 21 _R in the airtight state from the communication passage 26 Then, the second piston 22 moves leftward due to the supplied auxiliary air pressure, and accordingly, the main shaft 11 moves leftward against the urging force of the first piston, and stops at the left switching position. I do.

In the left switching position, the first output port 9 and the first discharge port 7 communicate with each other by the space between the small diameter portion 12a of the main shaft 11 and the shaft hole 5, and the space between the small diameter portion 12b of the main shaft 11 and the shaft hole 5 is provided. Input port 6 and second output port depending on space
An operation state in which 10 communicates is obtained.

When the main shaft 11 moves between the two positions in this way, the squeeze packing 15 is brought into contact with the sliding portion 39 of the seal sliding portion 45 formed in the valve seat 37 of the shaft hole 5 as the main shaft 11 moves. When the squeeze packing 15 slides and reaches the seal portion 38, the squeeze packing 15 slides a small distance in the tightened state and stops at the switching position. In this switching position, the squeeze packing 15 seals with a restoring force due to tightening.

Therefore, the sliding distance and frictional resistance of the squeeze packing 15 with the seal portion 38 can be reduced, the wear of the squeeze packing 15 can be reduced, and the life can be extended. Further, it is not necessary to machine the inner peripheral surface of the sliding portion 39 of the valve seat 37 with a high surface roughness, so that the machining cost can be reduced. In addition, by preventing the stick phenomenon from occurring, the operability at the start of work can be improved, and the durability of the switching valve can be improved.

Second Embodiment FIG. 3 is a sectional view showing a switching valve according to a second embodiment of the present invention, and FIG. 4 is a sectional view showing details of a main part of the switching valve.

The second embodiment has substantially the same structure as the first embodiment, but is applied to a switching valve in which a squeeze packing 40 is fitted to an annular valve seat 37 formed on the inner peripheral surface of the shaft hole 5. , A seal sliding portion 44 having a stepped structure on the large diameter portions 13 and 13a of the main shaft 11.
Is different from the first embodiment.

In detail, for example, in the large diameter portion 13a formed on the left side of the main shaft 11, the seal sliding portion 44 of the large diameter portion 13a
Is formed from a sliding portion 41 and a sealing portion 42, and this sealing portion
The diameter of the sliding part 41 is different from that of the sliding part 41, and the diameter of the sliding part 41 is so small that the inner peripheral surface of the squeeze packing 40 does not come into contact with it. In addition, the seal portion 42 has a curved surface 43 having a curved cross-sectional shape which is continuous with the sliding portion 41 and gradually increases in diameter toward the left side so as to correspond to the shape of the distal end of the squeeze packing 40. Is formed.

Regarding the operation and effect of the second embodiment, when the main shaft 11 moves in the direction of the arrow, the sliding portion 41 of the seal sliding portion 44 formed on the large diameter portion 13a of the main shaft 11 slides in contact with the squeeze packing 40. Then, when the seal portion 42 reaches the squeeze packing 40, the seal portion 42 of the squeeze packing 40 slides for a short distance while tightening the squeeze packing 40, and stops at the switching position. In this switching position, the squeeze packing 40 performs sealing with a restoring force due to tightening.

Therefore, in this case, the relative sliding distance and the frictional resistance of the squeeze packing 40 can be further reduced, and the wear of the squeeze packing 40 can be further reduced. Since the switching valve of this embodiment has a non-neutral type structure, the squeeze packing performs a switching operation without entering a neutral state when the input pressure of the input port is switched from the output port to the output port. As a result, it is possible to reduce the consumption of the fluid and the noise at the time of switching.

As described above, the invention made by the present inventors has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and it can be said that various modifications can be made without departing from the gist of the invention. Not even.

For example, in the embodiment, for example, a 2-position 5-port switching valve has been described. However, the present invention is not limited to this, and a 2- to 4-port switching valve may be used as long as the switching valve has two positions.

Further, in the embodiment, for example, the indirect operation type switching valve using the pilot pressure has been described, but the invention is not limited thereto, and a direct operation type switching valve that directly moves the main shaft may be used.

In the above description, the invention made mainly by the present inventor has been described using the switching valve operated by pneumatic pressure, which is its application field, but the invention can also be applied to a switching valve operated by hydraulic pressure.

[Effect of the invention]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1). The elastic seal is a squeeze type, and the seal sliding portion of the shaft hole or the main shaft is formed of a sliding portion and a seal portion connected to the sliding portion, and the diameter is changed between the seal portion and the sliding portion. In addition, the sliding portion has a structure in which the interference of the elastic seal is greatly reduced or has a diameter that does not substantially occur. The interference is greatly reduced or substantially eliminated, and as a result, the sliding distance and frictional resistance of the elastic seal with respect to the seal portion can be reduced, and the wear of the elastic seal can be reduced to extend the life. it can.

(2). The sliding portion has a structure in which the interference of the elastic seal is significantly reduced or has an inner peripheral surface having a diameter that does not substantially occur, so that when processing the inner peripheral surface, a high surface roughness is required. It is not necessary to perform the processing, and the processing cost can be reduced.

(3). The sliding portion has a structure in which the interference of the elastic seal is significantly reduced or has an inner peripheral surface with a diameter that does not substantially occur, so that at least the sticking phenomenon occurs in the sliding portion. Therefore, the operability at the start of work can be improved.

(4). As shown in the above (1) and (3), the sliding distance and frictional resistance of the elastic seal can be reduced, the wear of the elastic seal can be reduced, and the life can be prolonged.
Since the sticking phenomenon does not occur in the sliding portion and the operability at the start of work can be improved, the durability of the switching valve can be improved.

(5). In the present invention, the non-neutral switching valve can be realized with the stepped structure, in which the sliding distance between the elastic seal and the seal portion is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a switching valve according to a first embodiment of the present invention;
FIG. 2 is a sectional view showing details of a main part of the switching valve, FIG. 3 is a sectional view showing a switching valve according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view showing details of a main part of the switching valve. It is. 1 ... Main valve, 2 ... Pilot valve, 3 ... Solenoid part, 4 ...
Main valve body, 5: shaft hole, 6: input port, 7: first discharge port, 8: second discharge port, 9: first output port, 10: second output port, 11: main shaft, 12 ... Small diameter part, 12
a: first small diameter portion, 12b: second small diameter portion, 13, 13a: large diameter portion, 14: first valve seat, 15: squeeze packing (elastic seal), 16: main pilot passage, 16a ... First sub-pilot passage, 16b Second sub-pilot passage, 17 End cover, 18 First fluid chamber, 19 First piston, 20
... Pilot valve body, 21 ... Second fluid chamber, _21L ... Left fluid chamber, _21R ... Right fluid chamber, 22 ... Second piston, 23
... Pilot discharge port, 24 ... third fluid chamber, 25 ... second
Valve seat, 26 ... communication passage, 27 ... plunger pin, 28 ... flapper, 29 ... flapper spring, 30 ... bobbin, 31 ... fixed core, 32
… Plunger, 33… poppet, 34… plunger spring, 35
... Solenoid coil, 36 ... Solenoid cover, 37 ... Valve seat, 38 ... Seal part, 39 ... Sliding part, 40 ... Squeeze packing (elastic seal), 41 ... Sliding part, 42 ... Seal part, 43 ...
Round surface, 44: Seal sliding part, 45: Seal sliding part.

Claims (1)

(57) [Scope of request for utility model registration] 1. A valve body having an axial hole formed in the axial direction and having an input port, an output port, and a discharge port communicating with the axial hole, and a valve body movably provided in the axial hole. A switching valve for switching a flow path between the ports, wherein a squeeze-type elastic seal that elastically expands and contracts in a radial direction is attached to one of the valve body and the main shaft. Alternatively, the other of the main shafts has a diameter substantially corresponding to the diameter of the sealing surface of the elastic seal, and the interference of the elastic seal during movement of the main shaft is small or substantially does not occur. Forming a sliding portion and a seal portion which is connected to the sliding portion in the axial direction and contracts and deforms the elastic seal with a large radial interference by a continuous movement of the main shaft; Switching valve, wherein a diameter to each other and the seal sliding portion of the stepped structure differs by the Department.